Various printing methods are used in printing machines. Non-impact printing (NIP) methods are understood as printing methods that do not require a fixed, that is, a physically unchanging printing forme. Such printing methods can produce different printed images in each printing procedure. Examples of non-impact printing methods include ionographic methods, magnetographic methods, thermographic methods, electrophotography, laser printing, and, in particular, inkjet printing methods. Such printing methods typically have at least at least one image producing device, for example at least one print head. In the case of the inkjet printing method, such a print head is configured, for example, as an inkjet print head and has at least one and preferably a plurality of nozzles, by means of which at least one printing fluid, for example in the form of ink droplets, can be transferred selectively to a printing substrate. In this process, it is important for the distance between the printing substrate and the image producing device to be kept as constant as possible, to allow image production to be synchronized over time, while at the same time avoiding damage to the image producing device.
In the inkjet printing method, for example, particularly when water-based inks are used, the printing substrate can become deformed, for example, forming ripples. Such ripples can entail the risk of damage both to print heads and to the printing substrate, and can also lead to low print quality, for example due to the different flight time lengths for droplets of printing fluid.
US 2012/0162299 A1 discloses a printing assembly that has a plurality of print heads and stationary guide elements in the region of the print heads.
Printing substrate that has been provided with a printing fluid is typically dried in a subsequent process procedure. Various apparatuses for enabling such a drying process are known. For example, an energy output device that is capable of removing solvents and/or initiating crosslinking reactions may be provided. It is known to move the energy output device in question from an active position to a different, deactivated position, for example for maintenance purposes.
US 2009/0013553 A1 discloses a printing machine having at least one dryer unit. The dryer unit has a dryer that can be moved, parallel to a plane that is occupied by the printing substrate within the dryer, into a maintenance position.
CA 2281212 A1 discloses a printing machine having a dryer, which is equipped with hot air nozzles and can be pivoted about a pivot axis to allow maintenance work to be performed on a printing unit.
EP 1445563 A2 discloses a dryer that can be raised to allow a web to be threaded in, and can also be displaced horizontally to allow maintenance work to be performed on the rollers beneath the dryer.
DE 10 2013 208754 A1 discloses a printing machine having a dryer, and describes a threading means in the region of a printing unit.
EP 2047992 A2 discloses a printing machine having a dryer.
DE 199 03 607 A1 discloses a flexographic printing machine with radially displaceable dryer units.
WO 2013/056292 A1 discloses a printing machine having a dryer, which can be moved together with a print head, and the spacing of which from one another cam be adjusted.
DE 10 2011 076899 A1 discloses a printing machine having an inkjet print head, a radiation dryer and a cooling roller.